The present invention relates to poly(ester-carbonates) and especially to poly(ester carbonates) with at least a portion of the hydroxyl groups supplied by bisphenols with the 4-carbon of each phenol covalently bonded to the same ring carbon of a carbocyclic or heterocyclic moiety.
Polycarbonates of various bisphenols including phenolphthalein are known from U.S. Pat. Nos. 3,036,036, 3,036,037 and 3,036,039 all to Howe (May 22, 1962), U.S. Pat. No. 4,078,999 to Pannell (Mar. 14, 1978) and U.S. Pat. No. 4,167,536 to Factor (Sept. 11, 1979). Polyesters of phenolphthalein, including phenolphthalein terephthalate, are known from references including British Pat. No. 1,179,400 (Jan. 28, 1970) and U.S. Pat. No. 3,523,078 (Aug. 4, 1970) of V. V. Korshak et al. Phenolphthalein is a well-known compound used as a pH indicator and as a laxative component and is prepared from phenol and phthalic anhydride by condensation reaction analogous to the preparation of bisphenol-A from phenol and acetone.
Poly(ester carbonates) are a known class of polymers, being described for example in U.S. Pat. No. 3,169,121 to Goldberg (Feb. 9, 1965), U.S. Pat. No. 4,156,069 of Prevorsek et. al. (May 22, 1979) and in our copending, commonly assigned application entitled "Poly(ester-carbonate) With High Glass Transition Temperature", Ser. No. 088,782, filed Oct. 29, 1979. These polymers are formed by a condensation of a bisphenol such as bisphenol-A, phosgene and a dicarboxylic acid or acid halide such as terephthalic chloride (also called terephthaloyl chloride), with the moles of bisphenol approximately equal to the combined moles of phosgene and acid or acid halide. As described in U.S. Pat. No. 4,156,069 the most desirable combination of properties--including melt processability, high glass transition temperature, high molecular weight as indicated by specific viscosities in the range of 0.5 to 1 and high Izod impact resistance--are achieved when the molar ratio of phosgene to acid chloride is near 1 (such as about 0.8:1 to 1.2:1) and where the distribution of polycarbonate and polyester linkages are relatively random, without the presence of large polyester and large polycarbonate blocks.
A different type of poly(ester carbonate) is described in U.S. Pat. No. 4,105,633 to Swart et al. (Aug. 8, 1978). It describes an alternating poly(ester carbonate) having aromatic moieties linked on one side by the acid-derived end of an ester linkage and on the other side by the alcohol-derived end of a carbonate linkage, such moieties being derived, for example, from 4-hydroxybenzoic acid. The poly(ester carbonates) of U.S. Pat. No. 4,156,069 have, by contrast, aromatic dicarboxylic acid-derived moieties (terephthaloyl) linked solely by the acid-derived ends of ester linkages, and also aromatic bisphenol-derived moieties (from bisphenol-A) linked, randomly, by either the alcohol-derived end of an ester linkage or the alcohol-derived end of a carbonate linkage. U.S. Pat. No. 4,105,633 also has aromatic bisphenol-derived moieties, but these are proportedly linked solely to the alcohol-derived end of an ester linkage.
While the poly(ester carbonates) described in U.S. Pat. No 4,156,069 have the desired combination of properties for many applications, for certain applications such as cookware, wire coatings, electrical parts and motor housings, dimensional stability above about 180.degree. C., as evidenced by glass transition temperature higher than this figure, is desirable.
Poly(ester carbonates) are described in copending application Ser. No. 088,782 having glass transition temperature at least about 200.degree. C. with a retention or at least minimal loss of other properties, especially as compared to the poly(ester carbonates) described in U.S. Pat. No. 4,156,069. These polymers have a disadvantage, however, of requiring the use of relatively expensive and difficult to prepare substituted tricyclic aromatic bisphenols. In general, they also require temperatures of 320.degree. C. or higher for melt processing.
Accordingly it is an object of this invention to provide poly(ester carbonates) having a glass transition temperature higher than 180.degree. C. with the retention or at least minimal loss of other properties, compared to the poly(ester carbonates) described in U.S. Pat. No. 4,156,069, with melt processability significantly below the decomposition temperature of the polymer and, preferably, without the use of expensive or hard to prepare monomers.